KNbO3：Fe环形腔被动相位共轭器

介绍有附加反射镜组成的KNbO_3:Fe环形腔自泵相位共轭器,实验演示了相位共轭光建立过程中各光束间的能量转移现象,并测得自泵相位共轭反射率R随入射角α、环形腔光束夹角2θ和入射光强I_4的依赖关系,在最佳条件α=23°和2θ=20°时,测得最大的相位共轭反射率R=36%。     

反射式相位延迟器的性能研究

多层介质反射镜在非正入射的时候,两个不同的偏振态之间会产生不同的相移。通过优化设计,入射角为45°,在1285～1345nm之间p,s波获得了270°±0.15°的相移和99.5%以上的反射率。对使用的膜系进行了每层光学厚度的误差分析。用离子束溅射技术制备相位延迟膜,在大气中对样品进行不同温度的退火,用分光光度计测试了光谱特性和用椭偏仪测试了相位特性。结果表明,未退火的样品在相应波段获得了267.5°±0.5°的相移和99.6%以上的反射率;根据拟合分析,最外层的误差和折射率与设计值的偏差是发生相移偏小的主要因素;随着退火温度的升高、折射率变小和物理厚度变大,相移将变小。     

异型高效相位共轭镜的性能研究

光折变晶体特别是光折变效应极强的钛酸钡晶体的出现,使人们在获得简便而又高效的 相位共轭反射镜方面有了新的突破。人们利用这种具有极低功率响应的光折变晶体,运用它 的自泵浦相位共轭效应,已获得反射率为30％—50％的相位共轭波输出。本文具体报导了在 钛酸钡晶体中,最佳利用普克尔斯系数λ_(42)的一种相位共轭镜设计。对常规BaTiO_3晶体相 位共轭反射镜,由于BaTiO_3晶体本身的折射系数很大(n=2.42),至使外界入射光束不可 能在晶体内折射后,在晶体内的传输光束能与晶轴正C方向成45°角配置(BaTiO_3的内全反     

异型高效双相位共轭镜

本文具体报导了一种异型高效双相位共轭镜的实验研究结果。与已公开报导的各种双相位共轭镜相比,它具有如下特点;此异型双相位共轭镜对两束入射的非相干调整极不灵敏,即两束入射光的夹角从7°至110°角域内变化时,两束入射光皆可获得它们各自的相位共轭波输出。此特性是现有各类双相位共轭镜所不及的。当两束入射的非相干光强度相等时(束比I_1/I_2=1),此异型双位共轭镜具有大于30％的相位共轭反射率输出(公开报     

利用两波耦合增强BaTiO_3晶体的自泵浦位相共轭反射

本文报道了利用BaTiO_3晶体的两波耦合和自泵浦效应,实现高位相共轭反射率的方法。给出位相共轭反射率R随两耦合光束之间的夹角2θ,以及光束强度比β变化的实验结果。在适当的条件下(2θ≈35°,β=2600),得到共轭反射率大于35。     

氧碘激光器相位延迟片的制备与性能研究

多层介质反射镜在非正入射的时候,两个不同的偏振态之间会产生不同的相移。利用矩阵法,根据菲涅耳公式和电磁场边界条件,推导出p,s波的相移。通过优化设计,入射角为54°,在1285~1345 nm之间p,s波获得了270°±1°的相移,同时也使反射率在 99 .5%以上。用离子束溅射技术制备相位延迟膜,用分光光度计测试了光谱特性和用椭偏仪测试了相位特性,在相应波段获得了 262. 4°±1. 8°的相移,同时也使反射率在 99. 6%以上。误差的主要来源是离子源工作特性会产生不均匀的过渡层和最外层会吸收一些水气、灰尘等也产生表面过渡层。由误差分析得出了制备过渡层的物理厚度和折射率的变化情况,最外层的厚度误差和折射率偏差是发生相移偏小的主要因素。     

纤维素基电致驱动纸智能特性的研究

利用压电理论中的正压电与逆压电效应,针对纤维素基电致驱动纸(Electro-active paper——EAPap)的智能特性进行了研究。结果表明:同一样品在0.15~0.35V/μm电场强度下,产生了逐步增大的驱动效应;0°,45°以及90°三种样品在0.35V/μm电场强度下,45°样品产生了最大的平面内应变,达到428×10–6m/mm。同时对三种样品的正压电效应进行了测定,45°样品在弹性区和塑性区的压电常数分别为53.2pC/N和504.0pC/N。利用XRD验证了电场激励前后样品的结晶度产生了变化。     

海面对激光的方向反射率分布研究

利用随机面元模型,对海面的激光方向反射率分布进行了理论分析,并对多种典型条 件下海面对激光的方向反射率分布进行了数值模拟。结果表明,海面的总反射率较低,约为1%～6% ,但在入射角超过40°后,总反射率快速增大。激光入射角为30°、海面风速为1～14m / s时,激光的方向反射率都比较大(0. 1～0. 48 sr范围内) 。     

光学薄膜中界面层和表面吸附层对相位延迟的影响

多层介质反射镜在非正入射的时候,两个不同的偏振态之间会产生不同的相移.根据空气与膜层、膜层之间的实际情况,建立了界面层和表面吸附层模型,并运用它分析相位延迟产生误差的原因.通过优化设计,入射角为 54°,在 1285~1345nm之间p,s波获得了 270±1°的相移,同时也使反射率在 99. 5%以上.用离子束溅射技术制备相位延迟膜,用分光光度计测试了光谱特性和用椭偏仪测试了相位特性,在相应波段获得了 262. 4±1. 8°的相移,同时也使反射率在 99. 6%以上.误差的主要来源是离子源工作特性会产生不均匀的过渡层和最外层会吸收一些水汽、灰尘等也产生表面过渡层.由误差分析得出了制备中过渡层的物理厚度和折射率的变化情况,最外层的厚度误差和折射率偏差是发生相移偏小的主要因素.     

低偏振超宽光谱分色膜设计与制备

可见/红外超宽光谱分色片是星载中分辨率光谱成像仪III 型光学系统中的重要光学薄膜器件。利用诱导透射原理,采用金属-介质膜系结构加非对称等效导纳匹配层,实现了45°入射时0.4~1.05 μm光谱高效透射,1.35~13 μm波段光谱高效反射,从而将入射光束分配到不同的光路。同时通过消偏振控制设计,获得了可见近红外波段低偏振灵敏度（LPS）。所研制的分色片可见近红外波段平均透射率大于85%,LPS小于4%;短波及长波红外波段平均反射率大于90%。     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers

A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.     

A rigorous proof of MIMO channel capacity’s increase with antenna number

It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output（MIMO） communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory.     

Diode-end-pumped Nd:YVO4/LBO lasers with 4.2W continuous-wave output at 457 nm

A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.     

Call for Papers

正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks